I have a strange problem that I cannot seem to solve. I perform an upgrade to -current every 1-2 weeks and for a month now I have this strange problem.

When booting from bsd.rd, packages are nowhere to be found. From http or ftp, I give the full path (eg ftp.cc.uoc.gr or ftp.fr.openbsd.org), specify the path to the files (pub/OpenBSD/snapshots/<arch>/) but I constantly get

They're "filesets" not "packages". Both end in .tgz but they have different contents.

Nameservers, even Google's 8.8.8.8, will not be able to resolve addresses if they are unreachable. It is possible you are attempting to use a NIC that is not working with bsd.rd. No functioning network means no resolved IP addresses.

This might be because of firmware requirements, or a change in firmware requirements -- some drivers changes might require specific firmware versions.

My advice is to look to a NIC firmware problem. More information from you -- such as a dmesg, or the output of "ifconfig" -- might lead to better advice.

Your dmesg is from bsd.mp, not bsd.rd. Is ale0 functional when running bsd.rd? Does "ifconfig ale0" produce the same status and configuration information on bsd.mp and bsd.rd? If they're the same, both show active connection and the same 192.168.1.64/24 configuration, then

While running the ramdisk kernel:

Inspect the contents of /etc/resolv.conf and the output of "route -n show -inet". Do you see an obvious problem? If not....

Ping the nameserver(s) mentioned in the /etc/resolv.conf. Can you ping each successfully? Can you ping 8.8.8.8 successfully? If not...